Intensity mapping from the sky: synergizing the joint potential of [O iii] and [C ii] surveys at reionization

Abstract

ABSTRACT We forecast the ability of future-generation experiments to detect the fine-structure lines of the carbon and oxygen ions, [C ii] and [O iii] in intensity mapping (IM) from the Epoch of Reionization (z ∼ 6–8). Combining the latest empirically derived constraints relating the luminosity of the [O iii] line to the ambient star formation rate, and using them in conjunction with previously derived estimates for the abundance of [C ii] in haloes, we predict the expected autocorrelation IM signal to be observed using new experiments based on the Fred Young Submillimetre Telescope (FYST) and the balloon-borne facility, Experiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) over z ∼ 5.3–7. We describe how improvements to both the ground-based and balloon-based surveys in the future will enable a cross-correlation signal to be detected at ∼10–30σ over z ∼ 5.3–7. Finally, we propose a space-based mission targeting the [O iii] 88 and 52 $\mu$m lines along with the [C ii] 158 $\mu$m line, configured to enhance the signal-to-noise ratio of cross-correlation measurements. We find that such a configuration can achieve a high-significance detection (hundreds of σ) in both auto and cross-correlation modes.